TruAirspeed vs GRF Snowtam
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
TruAirspeed
This utility calculates true airspeed, pressure altitude, density altitude, and Mach number. It accounts for compressibility effects and offers unit choices and keypad styles. Users can also input a correction factor for their airspeed indicator.
- True airspeed calculation
- Pressure and density altitude calculation
- Mach number calculation
- Compressibility effects accounted for
- Choice of input/result units
- Calculator or telephone keypad options
- Airspeed indicator correction factor
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TruAirspeed is a True Airspeed Calculator for the iPhone and iPad. It's a bit different from other true airspeed calculators, in which the pressure altitude is an input. This requires resetting the altimeter to the standard sea level pressure of 29.92"Hg to read the pressure altitude. With TruAirspeed, you input the indicated altitude and the Kollsman window's pressure setting — the app then calculates the pressure altitude, density altitude, true airspeed and mach number for you. The calculations involved take full account of compressibility effects, but not shock waves, so it's limited to subsonic, non-transonic flight only. You have a choice of units for inputs and results, and you may choose either a calculator-style keypad (top row: 7-8-9) or a telephone-style keypad (top row: 1-2-3). You may also set a correction factor for your bird's airspeed indicator/pitot-static system, if you know it (mine is 0.95).
GRF Snowtam
Decode aviation weather reports with this tool. It handles Global Reporting Format (GRF) and older Snowtam formats, converts visibility and temperature units, and calculates altitude corrections for cold weather.
- GRF decoder
- Snowtam decoder
- MOTNE decoder
- Visibility converter
- Temperature converter
- Altitude correction calculator
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Complete and Accurate GRF decoder (New format GRF - global reporting format) to decode RCAM. Complete and Accurate Snowtam decoder (old format - used in Russia). MOTNE Decoder (Old format for Runway Condition Code) Converter for U.S. Visibility SM/m table, and temperatures Altitude correction calculator for cold Temperatures enjoy!
Screenshots
Verdict
The clearest difference is review sentiment: TruAirspeed at 71% against GRF Snowtam's 0%. TruAirspeed also leads on price (Free vs $1.99) and rating (4.1 vs 1.0). GRF Snowtam's advantage is update cadence (every 4 months vs every 24 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
TruAirspeed is free to download; GRF Snowtam costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
TruAirspeed holds the better App Store score, 4.1 against 1.0. That said, the two scores are not equally well evidenced: TruAirspeed has 8 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 71% of TruAirspeed's written reviews are positive against 0% of GRF Snowtam's.
TruAirspeed ships an update every 24 months, GRF Snowtam every 4 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.
| Parameter | TruAirspeed | GRF Snowtam |
|---|---|---|
| Price | Free — better | $1.99 |
| Rating | 4.1 (8 ratings) — better | 1.0 (1 ratings) |
| Positive reviews | 71.4% of reviews — better | 0.0% of reviews |
| Number of ratings | 8 — better | 1 |
| Update frequency | Every 24 months | Every 4 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free — better | Paid |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.6 | 15.6 |
| Further details — not scored | ||
| Size | 8 MB | 9 MB |
| Age rating | 4+ | 4+ |
| Developer | James Petty | Pedro Isidoro |
Customer experience
TruAirspeed
GRF Snowtam
In-app purchases
TruAirspeed
No in-app purchases
GRF Snowtam
No in-app purchases
Questions
Is TruAirspeed free?
Is GRF Snowtam free?
Which has better reviews, TruAirspeed or GRF Snowtam?
Do TruAirspeed or GRF Snowtam have ads?
Which is updated more often, TruAirspeed or GRF Snowtam?
Other comparisons
